What Is an Ostomy?
An ostomy is a surgically created opening (called a stoma) that allows bodily waste — either stool or urine — to exit the body through the abdominal wall into an external pouching system. Ostomies are performed for a variety of reasons, including colorectal cancer, Crohn's disease, bladder cancer, trauma, or bowel obstruction.
There are three primary types of ostomy, each involving a different part of the digestive or urinary tract. Understanding these differences is essential for proper management, product selection, and setting realistic expectations after surgery.
Colostomy
A colostomy is created from the large intestine (colon). The surgeon brings a portion of the colon through the abdominal wall to form the stoma. The location along the colon determines the consistency of the output.
- Ascending colostomy: Liquid to semi-liquid output; high in digestive enzymes; skin irritation is a common concern
- Transverse colostomy: Soft to semi-formed output; located on the upper abdomen
- Descending / Sigmoid colostomy: Formed stool similar to normal bowel movements; most common type
Who gets a colostomy? People with colorectal cancer, diverticulitis, rectal trauma, or bowel obstruction are common candidates. A descending or sigmoid colostomy may be reversible depending on the underlying condition.
Pouching: Closed-end pouches (changed 1–2x daily) or drainable pouches are used. Some people with sigmoid colostomies practice colostomy irrigation to regulate output without wearing a full pouch.
Ileostomy
An ileostomy is created from the small intestine (ileum), typically when the entire colon must be removed or bypassed. Because the stool bypasses the colon — where water absorption occurs — the output is liquid to pasty and contains active digestive enzymes.
- Output is continuous throughout the day
- High enzyme content makes output very caustic to peristomal skin
- Dehydration and electrolyte imbalance are significant risks
- Certain medications may not absorb properly (check with your pharmacist)
Who gets an ileostomy? People with ulcerative colitis, Crohn's disease, familial adenomatous polyposis (FAP), or colorectal cancer requiring total colectomy.
Pouching: Drainable pouches are essential; a good skin barrier/wafer is critical to protect peristomal skin from enzymatic output.
Urostomy (Ileal Conduit)
A urostomy is created to divert urine when the bladder is removed or can no longer function. The most common type is an ileal conduit, where a short segment of the ileum is used as a conduit to carry urine from the ureters to the stoma.
- Output is continuous urine (not feces)
- Stoma output is clear to yellow; mucus strands are normal
- Urine is acidic and can irritate skin if the pouch seal fails
- Urinary tract infections (UTIs) are a common concern
Who gets a urostomy? People with bladder cancer, severe bladder dysfunction, spinal cord injuries, or conditions requiring cystectomy (bladder removal).
Pouching: Urostomy pouches have a one-way valve and a drain spout at the bottom for emptying. A nighttime drainage bag is often connected during sleep to prevent overfilling.
Side-by-Side Comparison
| Feature | Colostomy | Ileostomy | Urostomy |
|---|---|---|---|
| Source organ | Large intestine | Small intestine | Ileum (conduit for urine) |
| Output type | Stool (formed to loose) | Stool (liquid to pasty) | Urine |
| Output frequency | 1–3x daily (or controllable) | Continuous | Continuous |
| Skin risk | Moderate | High (enzymatic) | Moderate (acidic) |
| Pouch type | Closed or drainable | Drainable only | Urostomy (with drain spout) |
| Reversible? | Sometimes | Sometimes | Rarely |
Living Well with an Ostomy
Regardless of ostomy type, most people return to full and active lives after surgery — including swimming, travel, working, and intimacy. A Wound, Ostomy, and Continence (WOC) nurse is your most valuable resource for learning proper pouching technique, troubleshooting leaks, and selecting the right products for your body and lifestyle.